The relationship between structure and function of macromolecules is of fundamental importance in the understanding of biological systems. These relationships are important to understanding, for example, the functions of enzymes, structure of signalling proteins, ways in which cells communicate with each other, as well as mechanisms of cellular control and metabolic feedback.
Genetic information is critical in continuation of life processes. Life is substantially informationally based and its genetic content controls the growth and reproduction of the organism. The amino acid sequences of polypeptides, which are critical features of all living systems, are encoded by the genetic material of the cell. Further, the properties of these polypeptides, e.g., as enzymes, functional proteins, and structural proteins, are determined by the sequence of amino acids which make them up. As structure and function are integrally related, many biological functions may be explained by elucidating the underlying structural features which provide those functions, and these structures are determined by the underlying genetic information in the form of polynucleotide sequences. In addition to encoding polypeptides, polynucleotide sequences can also be specifically involved in, for example, the control and regulation of gene expression.
The study of this genetic information has proved to be of great value in providing a better understanding of life processes, as well as diagnosing and treating a large number of disorders. In particular, disorders which are caused by mutations, deletions or repeats in specific portions of the genome, may be readily diagnosed and/or treated using genetic techniques. Similarly, disorders caused by external agents may be diagnosed by detecting the presence of genetic material which is unique to the external agent, e.g., bacterial or viral DNA.
While current genetic methods are generally capable of identifying these genetic sequences, such methods generally rely on a multiplicity of distinct processes to elucidate the nucleic acid sequences, with each process introducing a potential for error into the overall process. These processes also draw from a large number of distinct disciplines, including chemistry, molecular biology, medicine and others. It would therefore be desirable to integrate the various process used in genetic diagnosis, in a single process, at a minimum cost, and with a maximum ease of operation.
Interest has been growing in the fabrication of microfluidic devices. Typically, advances in the semiconductor manufacturing arts have been translated to the fabrication of micromechanical structures, e.g., micropumps, microvalves and the like, and microfluidic devices including miniature chambers and flow passages.
A number of researchers have attempted employ these microfabrication techniques in the miniaturization of some of the processes involved in genetic analysis in particular. For example, published PCT Application No. WO 94/05414, to Northrup and White, incorporated herein by reference in its entirety for all purposes, reports an integrated micro-PCR apparatus for collection and amplification of nucleic acids from a specimen. U.S. Pat. No. 5,304,487 to Wilding et al., and U.S. Pat. No. 5,296,375 to Kricka et al., discuss devices for collection and analysis of cell containing samples. However, there remains a need for an apparatus which combines the various processing and analytical operations involved in nucleic acid analysis. The present invention meets these and other needs.